1. Field of the Invention
This invention relates to exercise apparatus and particularly to the type involving the user pulling on cables to lift weights.
2. Prior Art
Since the introduction of resistance exercises into the training regimen of most all sports, major attention has been directed toward the development of apparatus that develops muscles of the hips, legs and lower back. A large variety of exercises are performed corresponding to the complex involvement of numerous muscle groups. Because each of the exercises requires a unique accomodation of the apparatus to the size and range of motion of the user, the trend has been to develop a particular apparatus for a very limited number of exercises. An alternative approach has been to provide a bench with one resistance means for each exercise.
For example, (U.S. Pat. No. 4,407,495) an apparatus for developing the knee extensors provides for the user to sit on a bench with a lever arrangement at one end positioned to perform knee extensions and a rack at the other end of the bench to perform bench presses.
A number of disclosures, (U.S. Pat. Nos., 4,423,865, 4,405,128, 432,896) disclose benches in sections that may be inclined at appropriate angles to perform exercises with free weights, situps, etc. U.S. Pat. No. 4,423,865 discloses a bench comprising sections supported on telescoping tubes which is useful for exercises involving free weights.
The use of cables threaded over a pulley and attached to weights has been in use for many years,(see, e.g., U.S. Pat. No. 4,361,323). In order to provide a uniform resistance throughout the entire range of motion, a cable having one end attached through a pulley to weights may be wound around a wheel so that the torque required to lift the weights by turning the wheel in constant. In this configuration, a support for the user is fixed in a position suitable for a single exercise.
None of the apparatus in the prior art provides to a user of any size the means of performing the large number of exercises--knee extensions, back extensions, leg curls, glute extensions, abdominal crunches, knee raises, etc. that is provided by the apparatus of this invention which is also characterized by simplicity and economy of construction.
Furthermore, none of the apparatus in the prior art makes allowance for the fact that in performing exercises involving flexion and extension of the knee joint, the range of motion of the knee joint depends on the angular position of the hip. The flexion of the knee joint is 40 degrees greater when the hip joint is flexed 90 degrees compared to when the hip joint is straight. (See Physiology of the Joints by I. A. Kapandji vol. 2, page 77, published by Churchill Livingston, N.Y., 1970). Therefore, in order to move the knee joint in its fullest range of motion when performing important exercises such as leg curls and knee extensions, it is necessary that the hips be flexed when performing flexion and extension of the knee joints.